Warping
When you change the tempo or pitch of a cue in KTPlayer, it doesn't alter the underlying audio file. Instead it warps the audio: stretching or compressing it in time to reach the new tempo while keeping pitch unchanged, or shifting the pitch while keeping tempo unchanged.
Two side effects
- Possible slight drop in audio quality. The further you warp from the original, the more audible the processing becomes. At small adjustments (within 5%) the effect is inaudible; at larger adjustments you may hear smearing, particularly on percussive transients such as snares, claps, and hi-hats.
- Increase in CPU load. Warping is compute-intensive. The quality setting in Preferences lets you trade quality against CPU usage.
Warping quality settings
In Preferences → Devices → Warping quality, choose from:
- Fastest. Lowest CPU usage, lowest quality. Use this on older Macs that cannot keep up with Medium or Best.
- Medium (default). The right balance for most rehearsal and performance setups.
- Best. Highest quality, highest CPU usage. Use this if you hear artifacts on heavily warped content and your Mac has CPU headroom.
Medium is the right setting for most shows. If you hear stuttering during playback, drop to Fastest before investigating other causes.
Warping breaks LTC
If a cue has an LTC (Linear Timecode) channel, warping that cue's tempo or pitch makes the LTC stream non-functional: the signal does not survive warping. The timecode depends on the audio playing at its authored rate, so as soon as a cue is warped the LTC on that cue stops being meaningful and downstream systems lose sync.
If you need to warp a cue that has LTC, you have two options: accept that LTC drops on that cue and tell the lighting and video operators in advance, or request a custom alteration from KeyboardTEK.